Michael Portillo and Boris-Come-Lately have joined Nigel Lawson in the Times newspaper's campaign to persuade Britain to leave the EU and, in the process, quite possibly propel Mayor Johnson into No 10 and the acting-editor of the newspaper into even better favour with Rupert the Rogue.

Who would have thought that another renegade Nigel would rush so boldly to elbow Nigel Farage aside? Or that they'd both feel a bit light on the history of our turbulent continent? I read another speech by a far more obscure British politician this week which reminded his audience that we have a centuries-old interest in who controls the "mouth of the River Scheldt" which, as diligent schoolboys know is on the Dutch coast. That interest has not gone away just because Lord Lawson thinks it has.

I don't think Portillo's intervention adds much to the debate. It largely echoes the Lawson analysis. An ex-Labourist turned ex-Thatcherite, ex-defence secretary and ex-frontrunner who failed to defeat IDS for the Tory leadership deserves to end his political career in impotent exile, making easy-listening programmes for TV. It is a dreadful fate. Boris is basically a lightweight, too, but a far more formidable politician.

Nigel Lawson, Margaret Thatcher's boom-and-bust chancellor from 1983 to their own bust in 1989, is in a very different league, one of nature's political heavyweights. That doesn't make him right on Europe any more than his contrarian outlier's views on global warming make him right and Charlie Windsor wrong – he's at it again. But Lord Lawson, now 81, is a clever man who commands attention. Nowadays, he is also a thinner one, despite all those delicious suppers daughter Nigella must have put his way.

Fair-weather trimming

Since I vividly recall that first Lawson, then his predecessor, Sir Geoffrey Howe, had resigned over Thatcher's relentlessly hostile attitude to Europe, I assumed I'd find evidence of more fair-weather trimming by someone who should know better. After all, didn't Lawson "shadow the Deutschmark" as chancellor without telling Mrs T as a means of squeezing indisciplined inflation?

Alas, I was disappointed. His memoirs, particularly a prescient speech at Chatham House in January 1989, are easily squared with this week's thunderbolt, at least in economic terms (the politics are awful), though not, as the Guardian editorial also pointed out, with his more recent and tolerant "wait-and-see" pronouncements on the eurozone crisis.

Lawson now predicts that David Cameron's promised "renegotiation" of the EU treaties and powers will yield "inconsequential" results, much like Harold Wilson's trivial renegotiation in 1974-75 which prompted young Nigel (and young Margaret, too) to vote Yes to the Common Market in the 1975 referendum. I'm sure he's right and also sure that a much more sceptical electorate will see through the ruse in 2017 – or whenever the big vote comes. He'll be voting No with the other Nigel.

Lawson's argument is that the EU is not what it was – or could have become – when he was a supporter from the 1950s onwards. Nor is the exchange rate mechanism (ERM), membership of which he and Howe failed to press on Thatcher (John Major succeeded briefly, with dire results), the same as the eurozone's monetary union inside a single currency which events are now forcing to change into a form of banking and fiscal union run from Berlin and Frankfurt.

Instead of becoming an outward-looking beacon of free trade in a globalised world, the EU has become introverted, bureaucratic and steadily weaker. All true. What's more, he now asserts, it has served its purpose in helping to refocus British economic ambitions in the 70s – away from commonwealth trade, bolshie unions, exchange controls and lax management – towards the rich European export market. But times change: the emerging Asia/Brics-orientated world should now be our target market.

Yes, indeed. As I never tire of reminding my eurosceptic chums, no one in Brussels or Berlin is stopping British manufacturers of goods or services from exporting to India and China. The Germans themselves manage quite well – and, whisper it not, we're doing better, too. But does the case made by the Two Nigels – Lawson and Farage – now make sense in the long-term British interest? I'm not persuaded.

World view

My first response was to wonder what Lord Lawson read at university that shaped his world view? With minimal research I found he had been a keen sixth form mathematician who won a scholarship (clever boy) to read law at Christ Church, Oxford, only to be persuaded that it was a poor preparation for a legal career (good advice, I suspect). So he read politics, philosophy and economics (PPE) like so many wannabe politicians nowadays, with philosophy his speciality. It trained him to think clearly and cut through the crap, he explains.

Fine. He makes a powerful case for saying that the eurozone demonstrates both political contempt for democracy and a recipe for economic centralism and under-performance, much as he warned at Chatham House in 1989. Worse, meddling from Brussels threatens not merely to put the City's house in better regulated order (Lawson is a member of the Tyrie banking commission) but to hurt ("a frenzy of regulatory activism ... foolish and damaging") its position as a world leader, the one undisputed British claim to economic importance in 2013.

Too many British firms now feel cosy inside the European club, it's time to get their suitcases out to sell to the world, says Lord Lawson, whose own travel was experienced mostly as an FT journalist, political bagman and politician: as much a career elitist as any Cameron, Miliband or Clegg today. The economic downside is exaggerated save for the one quantifiable UK gain – our £8bn net annual membership fee.

This is A-level Ukip and Lord Lawson, as the tone of his memoirs reminds us on every impatient "I-was-right" page, is a clever men, a charming one, too, when mellow. I bumped into him in a Whitehall street only the other day and adjusted his collar which was turned up. Delightful company.

But my reading of his Times article sagged when I read – quite early on – that "there is no threat from German militarism" because the EU has achieved its original and admirable aim of putting the "German tiger in a European cage". Oh really? In one sense he's right, after a century of traumatic wars and humiliation modern Germany is close to functionally pacifist, sheltering complacently under the US military umbrella, prepared to switch to the Russian one, I sometimes suspect, if the gas tap gets turned off in winter. Of all the continents, Europe is now the most energy vulnerable. Chancellor Merkel's odd turn against nuclear power makes things worse.

Muddy harbours

But nothing is certain and, as Lord Lawson often says, nothing is for ever, except that the harbours of the muddy River Scheldt – last fought over in 1944 – still point our way, a traditional stepping point for would-be invaders from a combination of any of our near-neighbours with whom it is always possible we will one day fall out. Unlikely, I know. But we always think that. For 500 years Britain has sought to prevent a hegemonic power emerging across the Channel.

Myself, I share much of Lord Lawson's dismay about current developments within the EU and never supported sterling's membership of the eurozone as so many much cleverer (now strangely silent) people did. I fear for its future – and therefore for ours, too. But I have equally pressing doubts about Britain's ability to go it alone in the 21st century with or without the help of the buccaneering bankers of the City.

After all, it's not as if our own currency zone is doing so well. Unemployment here is better than the eurozone (good), negative growth since 2008 almost as bad, our deficit is worse, and the regional imbalances between London and the rest of the country is painful. If we're so smart and enjoying so much freedom of economic manoeuvre outside the zone, why aren't we doing better?'

• This article was amended on 10 May 2013. The original article said the mouth of the river Scheldt is on the Belgian coast. It sits, in fact, within the neighbouring Dutch province of Zeeland.